Although predominantly red due to the high quantities of iron oxide on the surface, ice-caps can be seen at both poles similar in nature to our Arctic and Antarctic. These are however composed mostly of dry ice (frozen carbon dioxide as opposed to water), although in the north it is known that the dry ice turns to a gas during the summer, leaving some water ice behind, but it is not known whether this happens in the south.

Life on Mars?

Since last century, Mars has been a favourite subject of science-fiction writers. This is in part due to the observations of Percival Lowell, an American astronomer whose studies led him to believe that the strange, line-like markings he could see on the surface were canals. Stories of invasions from Mars such as War of the Worlds by H.G. Wells proved to be extremely popular. When Orson Welles read out an edited version of War of the Worlds over the radio in the 1950s, the people of America were thrown into a panic, believing that they were under attack from martians.

The picture shown, Surface of Mars painted by Chesley Bonestell ( Copyright: Bonestell Space Art), is typical of artists influenced by such writers, depicting a very Earth-like scene and canal-like water-ways. The reality is far more bleak, and though there is little doubt that the channels were carved by water, it is also known that liquid water cannot exist under present conditions on Mars, which suggests that Mars may have once been significantly different.

Years after War of the Worlds panicked America, NASA probes proved beyond reasonable doubt that the canals were in fact natural features, and when both the USSR and the US sent landers to the surface they found no evidence of any life, intelligent or not. What they did find was evidence that Mars used to have significant amounts of water on the surface, maybe even oceans, and that there were also once active volcanoes. This was, however, a long time ago, and nowadays Mars is relatively dead, except for occasional high winds and dust storms.

Most scientists have dismissed the claims, but it has once again stirred up the argument for life having existed on Mars, giving NASA some much needed support for its plans to study the Red Planet in greater detail. The debate still continues.

Mission to Mars

Recent interest in Mars, coupled with the conjunction of Mars with Earth in 2003, has resulted in several simultaneous missions. NASA's orbiter Mars Odyssey was launched on April 7 th 2001, and went into ‘overtime' in August last year, having discovered vast reservoirs of water ice and completed 10,000 mapping orbits. NASA also achieved great success with its rovers Spirit and Opportunity, which arrived early in 2004. Images sent back to Earth include several of ‘dust devils' – clouds of wind-blown dust, which experts think could be seasonal. NASA's most recent lander, Phoenix, is currently exploring the Martian Arctic. Nor is NASA the only organisation to have contributed to Martian exploration; ESA's Mars Express successfully went into orbit in December 2003, and has since discovered aurorae on Mars of a kind never before seen in the solar system. An aurora is a display of light caused by the alignment of charged particles in a magnetic field, and terrestrial aurorae are known as the Northern Lights.

Recently, photographs from NASA's Mars Global Surveyor appear to display evidence that water has flown recently on the Martian surface. A comparison of images taken in 1999 and 2005 appears to show a recent deposit on the surface, that may have been cause by the flow of liquid water.

Sadly, Beagle2, the British led lander companion of Mars Express (a project involving several members of the University of Leicester), was lost after it deployed from Mars Express and began its perilous journey to the surface. Lander control could still be seen until recently at the National Space Centre in Leicester, and it is hoped that Britain will not have to wait long for another opportunity to explore the Red Planet.